Chinese efforts to persuade North Korea to rein nuclear programme have failed:

Vastavam web: Donald Trump said on Tuesday that Chinese efforts to persuade North Korea to rein in its nuclear program have failed, ratcheting up the rhetoric over the death of an American student who had been detained by Pyongyang.Trump has held high hopes for greater cooperation from China to exert influence over North Korea, leaning heavily on Chinese President Xi Jinping for his assistance. The two leaders had a high-profile summit in Florida in April and Trump has frequently praised Xi and resisted criticizing Chinese trade practices.

It was unclear whether his remark represented a significant shift in his thinking in the U.S. struggle to stop North Korea’s nuclear program and its test launching of missiles or a change in U.S. policy towards China.”I think the president is signalling some frustration,” Christopher Hill, a former U.S. ambassador to South Korea, told MSNBC. “He’s signalling to others that he understands this isn’t working, and he’s trying to defend himself, or justify himself, by saying that at least they tried as opposed to others who didn’t even try.”Officials and experts have been saying for months that North Korea could conduct a sixth nuclear test at any time, and satellite images periodically show such movements.